Ignition-dynamo.



C. T. MASON.

IGNITION DYNAMO.

APPLICATION I'ILED 111 11.23, 1912.

. 1,081,760 Patented Dec. 16, 1913.

UNITED STATES parent): OFFICE.

qnnnnris THOMAS mason, or'sum'rnrt, sou'rri CAROLINA, nssionon. TO sums-13:3,,

' EL CTRI AL COMPANY, A COB PIORA'JJJIQN OF SOUTH GARQLINA.

mmrrou-nrnnmo.

matted.

Specification of Letters Patent. Patented Dec. 16,1913.

REISSUED To all whom itmay concern: 1

Be it known that I, CHARLES THOMAS MASON, a citizen of the United States, residing at Sumten, in the countyof Sumter and State of South Carolina, haveinvented certain new and use 111 Improvements in Ignition-Dynamos, 0 which the following me specification, reference being had to the accompanying drawing.

My i'vention relates to electric generators, an particularly to that class of generators used for igniting the charge in internal combustion engines, for firing electric primers used inartillery, and for igniting blasting caps. Such machines are commonly termed ignition dynamosf, and

whilemy invention is peculiarly applicable to su clfmach-ines it will. be understood that the principle of construction may be used in a dynamo for any purpose.

My invention consists more in the principle of design than in the actual mechanica arrangement of the parts of the dynamo,

- as numerous arrangements will be obvious to those skilled in the art. All such arrangements W111, however, embody the principle of design which. I claim is new.

' As my invention is' particularly adapted to ignition dynamoal describe same asapplied thereto, and will point out the difler-' once-between my design and existing types L and enumerate theobj ectsacconiplished and the advantages attained. Ignition dynamos are, broadly speaking, of two general types, one of which has an armature adapted to be moved in the-magnetic field, and containing a winding in which the current is. generated. -The other type has. a stationary winding, and a mQYablerotor so positioned that it causes the "magnetic flux to pass through the winding, thereby generatinga. current. I In all types thegeneratlonof current 1s produced by altering the path of the mag.- neticflux, and: in many machines this path e is alternately established, broken and reversed through the winding; in every case the armature orrotor is subjected to a res" versalofflux through its mass, except in ,Iwthe armature is open to the 0 jections that certainmachines where the entire magnetic tructure for producing the fielg' is revolved.

Thetype 0 machine having winding on the winding spaceis necessarilylimited, the windings'are difiicultto. insulate,- the wire turns on the ends are practically inactive, and actually impede the current generated, the circuits must be brought out through sliding contacts which are liable to give trouble and which introduce an extra resistance in the circuit, a special grade of iron laminae must be used for the armature, and it is very difficult to advance and retard the position of the spark in the case of alternating current machines, as the intensity of the spark varies with the relation of the armature to the pole pieces.

In the rotor type many of the foregoing objections remain, and, in addition, many of these machines produce four impulses of current per revolution when a-- permanent magnet field is used, there are usually four air gaps. instead of two as is the case with the wound armature type, and the difficulty .advantages of both tvpes, as hereinafter 'de-.

scribed, and which broadly consists of the employmentof a stationary magnet and a rotor in connection therewith, so positioned that the magnetic flux is established through the Winding, the rotor at all times maintaining t e same polarity in relation to the magnet. The importance of this method ofconstruction is very great when the advantages derived therefrom are considered. To make these fully evident, reference is had to the accompanying figures, in which Figure l is a diagram illustrating the principle of construct-ion of. a dynamo embodying my invention, Fig. 2 a side View of the same with the field member in one position, and Fig. 3 with the field member shiftedfrom the position shown in Fig. 2; Fig. 4.- is a detailed view of the rotor.

ldenotes a permanent magnet, between the poles @which is positioned the rotor comprising spaced magnetic inductor elements 2 and 3, carried by shaft 4, which is free to revolve. There is no space between the inductor members 2 and 3, and the inner cheeks of the magnet 1. The ends of the polar extensions 2 and 3 are .contiguous to the inner cheeks ofthe magnet poles, and may abut ,as shown directly against the same, in extended frictional contact therewith, during their entire rotation; but in any case must be maintained in continuously,-

flux therefrom without any' open air gapr As this is a close fit, air gapsare eliminated. As the inductor members 2 and 3 always maintain the same polarity as the extremities of: the magnet to which they are con- 0 neeted, there is no reversal of magnetic flux through them, and they may be made of the same material as the magnet; .or any magnetic material. They may be drop forgings. This eliminates the necessity for laminae in the rotor, and greatly increases the efliciency and speed of roperation. There being no reversal of fiuxin the rotor, there is no lag in this portion of the mag- Y netic circuit, as is the case with machines in which a reversal or stoppage of the flux takes place at every movement of the arma-j ture. The inductor members 2 and 3 are joined together to' form one rotating element, by means ofthe block 5. of suitable non-magnetic material. This block is omitted in Fig. l to more clearly. permit the operationof the dynamo to be understood.

6 and 7 are the ends of a normally stationary core 8 of any suitable form, upon 0 some portion of which is placed the windin 9. This core is referabIylaminated, an the ends of same are bored so as to permit the rotor formed of 2, 3 and 5 to move between them with only a small air'gap interveiling. Thepath for the flux from the end 6 ofthe core 8 to the end 7, through the part on which the coil is wound should be as short as possible. The length in Fig. 1 is somewhat exaggerated so' as to bring the 40 coil outside the magnet where it could be seen. The core 8 isfree to move angularly about the az'zis of the rotor as shown in Figs. '2 and 3, so that it can be placed in any position to bring its ends 6 and 7 in different relation 'to the inductor members 2 and 3. Fig. 2 shows what may be termed the normal or retard 'osition, the rotor moving-from right to le Fig. 3 shows the advanced position, the core having been revolved so that the rotormeets the ends G'and 7 sooner thereby advancing the spark. It will be observed that the winding space on 8 can be much larger than the space on a-wound armatu're, and every turn is effective, the shape of the space is such a that'ihe coil is easy to wind-and insulate,

all sliding contacts are eliminated -as the wires 10 and 11 maybe connected directly to the deviceto be operated, and that the intensity of the spark is the same either advanced or retarded, as the position of the core with respect to the'rotor makes absolutely no difierence in the variation of the magnetic flux through the core of the coil. This construction produces only two imsion ignition dynamos.

pulses of current per revolution ofthe rotor,

and is therefore adapted to be used in standard ignition systems running at engine. speed, without producing false explosions, or requiring timing cams. The necessity for revolving a large and heavy magnet st-ruct-ureis obviated, as a marked increase.

in efiiciency results from the absence of the necessity of reversing the flux through the rotor, and the-bringing out, as it were, of the magnet directly to the face of the coil carrying core 8'. v The operation of a dynamo constructed sis-described is as follows :-Considering the lefthand pole of the magnet 1 to be of N polarity, inductor element 2 is of. the same polarity, and remains so, regardless of any position-in which. it may be. The rotor as a whole, 'being in the position as shown in Fig. 1, the magnetic lines will flow from the N pole of magnet 1, through rotor element 2, to the end 6 of coil core 8, to end 7, to rotor element 3 to the S side of the magnet.

3 is always of the S sign. Asthe rotor revolves from right to left, elements 2'and 3 bridge the gap between the edges 12 and i 13, 14 and 15, as shown in Fig. 3, and magnetically short circuit the coil core 8. .This sudden change in the flux induces an electromotive force in the winding 9. The rotor, continuing to revolve, reaches-the position where element 3 is uppermost, and then a reversal takes place, .the path of the flux being from N to 2, to 7 through 8'to-6, to 3, to S. When the rotor reachesa posi tion the reverseof that shown inFig. 3, the coil core is again magnetically short-' circuited and the peak of electromotiveforce of opposite fpolarityfinduced in the coil. An oscillation of the armature will produce the same result, provided the rotor and core checks are properly proportioned.

I am aware that it is not new to use a stationary magnet and .awinding on a coil core, with a rotor between the two, but in all such structures the rotor simply revolved in a stationary field, and was subject to the same magnetic reversal as the winding on the coil core. The important feature of my invention'isthe employment'of the magnet with' movable inductor' members, which members at all times maintain the same polarity, and which serve to alter the path. of magnetic 'flux acting on "the winding; Every turn in my evil is effective, as there are no dead ends, the flux passing through ifzlhe wire insteadof the'wire through the While I have shown only one winding, it is obvious that more than one winding may be employed, and that the dynamo'may be used in combination with a circuit breaker,

and distributer and other auxiliarydevices such as commonly employed with high ten- I claim: 1. In an igniting dynamo, a U-shaped magnet, and a rotor having a path of travel which lies entirely within the space between the poles of-said magnet and comprising magnetic inductor elements in continuous magnetic contact relation with the inner cheeks of both 'magnet poles and thereby maintained of permanent and opposite polarity, together with a normally stationary current'generating coil and a. core therefor in inductive relation to said rotor.

extending longitudinally from pole to pole of the magnet and having suitable bearing supports, said rotor comprising a 'pair of axially separated magnetic members of permanent and opposite polarity having end surfaces in extended sliding contact with the inner faces of said magnet poles independently of said bearing supports, together with a normally stationary current generating coil and a core therefor in normally fixed inductive relation to said rotor.

4. In an ignition dynamo, a permanent field magnet comprising one or more individually integral U-shaped permanent magnets, said field magnet having axially alined apertures in opposite poles, a rotor having shaft extensions journaled in said apertures, and having a main body adapted to be magnetized by said permanent magnet, together with a normally stationary current generating coil in inductive relation to said rotor.

5. In an ignition dynamo, a substantially U-shaped permanent magnet having axially alined bearing apertures in its poles, a rotor journaled in said apertures and having end portions of magnetic material of permanent and opposite polarity in magnetic and conductive relation respectively to the inner faces of said poles but magnetically insulated from each other, together with a nor-. 'mally stationary current generating coil and core therefor in inductive relation to said rotor.

6.- In an ignition dynamo, a permanent magnet having poles spaced apart and having inner cheeks opposite and parallel to each other, and a rotor between said magnet poles having a right cylindrical path of rotation and end surfaces of magnetic material rotating in contact with'the inner parallel cheeks of the field poles, but magnetically insulated from each other, together with a normally stationary current generating coil in inductive relation to said rotor.

7. In an ignition dynamo, a U-shaped magnet, and a rotor having a path of travel lying entirely within the space between the magnet poles and comprising magnetic inductor elements of permanent and. opposite polarity, together with a normally stationary generating coil and core in direct inductive relation to said rotor and shiftable bodily with respect to the path of movement thereof whereby the timing of the generated electromotive force may be varied.

In testimony whereof I hereunto afiix my signature in the presence of two witnesses. CHARLES THOMAS MASON. Witnesses:

F. C.'MANN1NG, H. R. VAN DEVENTER. 

